Plasmodium ovale curtisi and Plasmodium ovale wallikeri are distinct species of malaria parasite which are sympatric throughout the tropics, except for the Americas. Despite this complete overlap in geographic range, these two species do not recombine. Although morphologically very similar, the two taxa must possess distinct characters which prevent recombination between them. We hypothesised t...

Most hymenopteran species exhibit conspicuous sexual dimorphism due to ecological differences between the sexes. As hymenopteran genomes, under the haplodiploid genetic system, exhibit quantitative differences between sexes while remaining qualitatively identical, sexual phenotypes are assumed to be expressed through sex-specific gene usage. In the present study, the molecular basis for express...

This study analysed how sex-specific features differed in male and female adult mandibles throughout the spectrum of vertical facial patterns (i.e., meso-, dolicho- and brachyfacial) and sagittal variations (the so-called skeletal Classes I, II and III; normal maxillo-mandibular relationship, maxillary prognathism vs. mandibular retrognathism, and maxillary retrognathism vs. mandibular prognath...

Symmetry and masculinity in human faces have been proposed to be cues to the quality of the owner. Accordingly, symmetry is generally found attractive in male and female faces and femininity is attractive in female faces. Women’s preferences for male facial masculinity vary in ways that may maximise genetic benefits to women’s offspring. Here we examine sameand opposite-sex preferences for both...

Sexual dimorphism is a widespread phenomenon and contributes greatly to intraspecies variation. Despite a long history of active research, the genetic basis of dimorphism for complex traits remains unknown. Understanding the sex-specific differences in genetic architecture for cranial traits in a highly dimorphic species could identify possible mechanisms through which selection acts to produce...

Several different models of sexual dimorphism in the South African australopithecines are compared with sexual dimorphism in the living primates. Australopithecine dimorphism is placed in an evolutionary context, and contrasting trends in the hominid and pongid lineages are shown. Evidence suggesting that the australopithecines were an extremely polytypic taxon is presented, and a high level of...

Two very small late Eocene anthropoid primates, Catopithecus browni and Proteopithecus sylviae, from Fayum, Egypt show evidence of substantial sexual dimorphism in canine teeth. The degree of dimorphism suggests that these early anthropoids lived in social groups with a polygynous mating system and intense male-male competition. Catopithecus and Proteopithecus are smaller in estimated body size...

Introduction: Anthropometric study is very important in the identification of sex especially when the body has been destroyed as a result of physical injury. The aim of this study, therefore, is to determine the presence of sexual dimorphism in the foramen magnum of skulls of North India region.. The sample comprised 96 skulls, of these skulls 50 are males and 46 females. The result obtained de...

Sex differences in parental care are thought to arise from differential selection on the sexes. Sexual dimorphism, including sexual size dimorphism (SSD), is often used as a proxy for sexual selection on males. Some studies have found an association between male-biased SSD (i.e., males larger than females) and the loss of paternal care. While the relationship between sexual selection on males a...

Sexual shape dimorphism is the differentiation of male and female organisms based on their shape variation; this definition was proposed for the use of geometric morphometrics analysis where the geometric features of the shape are analyzed without the influence of the size. Macaria mirthae (Lepidoptera: Geometridae) is a moth that inhabits different valleys in the north of Chile principally ass...